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García-García F, Acosta-Hernández ME, Beltrán-Parrazal L, Rodríguez-Alba JC. The Role of Neuroglobin in the Sleep-Wake Cycle. Sleep Sci 2023; 16:e362-e367. [PMID: 38196764 PMCID: PMC10773511 DOI: 10.1055/s-0043-1772806] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2022] [Accepted: 11/23/2022] [Indexed: 01/11/2024] Open
Abstract
Neuroglobin (Ngb) is a protein expressed in the central and peripherical nervous systems of the vertebrate. The Ngb has different functions in neurons, including regulating O 2 homeostasis, oxidative stress, and as a neuroprotector after ischemia/hypoxia events. The Ngb is a hemoprotein of the globin family, structurally like myoglobin and hemoglobin. Ngb has higher expression in the cortex, hypothalamus, thalamus, brainstem, and cerebellum in mammals. Interestingly, Ngb immunoreactivity oscillates according to the sleep-wake cycle and decreases after 24 hours of sleep deprivation, suggesting that sleep homeostasis regulates Ngb expression. In addition, Ngb expresses in brain areas related to REM sleep regulation. Therefore, in the present review, we discuss the potential role of the Ngb in the sleep-wake regulation of mammals.
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Affiliation(s)
- Fabio García-García
- Instituto de Ciencias de la Salud, Departamento de Biomedicina, Universidad Veracruzana, Xalapa, Veracruz, Mexico
| | | | - Luis Beltrán-Parrazal
- Instituto de Investigaciones Cerebrales, Universidad Veracruzana, Xalapa, Veracruz, Mexico
| | - Juan Carlos Rodríguez-Alba
- Instituto de Ciencias de la Salud, Departamento de Biomedicina, Universidad Veracruzana, Xalapa, Veracruz, Mexico
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2
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Lalovic B, Savant Landry I, Moline M, Reyderman L, Hussein Z. Exposure-Response Analyses of Polysomnography and Subjective Sleep Efficacy End Points From the Phase 3 Trials of Lemborexant, a Dual Orexin Receptor Antagonist for the Treatment of Insomnia. J Clin Pharmacol 2023; 63:498-511. [PMID: 36524428 DOI: 10.1002/jcph.2192] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Accepted: 11/29/2022] [Indexed: 12/23/2022]
Abstract
This report describes polysomnography and sleep diary exposure-response analyses from Study E2006-G000-304 (Study 304), a 1-month trial of 5- or 10-mg lemborexant, zolpidem, or placebo; and Study E2006-G000-303 (Study 303), a 6-month trial of 5- or 10-mg lemborexant or placebo. Studies 304 and 303 included 1006 (86%) and 956 (68%) (female) participants, respectively; >40% were ≥65 years, with individual lemborexant exposures derived from a previously described pharmacokinetic model. Linear mixed-effects analyses of polysomnography: latency to persistent sleep (LPS), sleep efficiency (SE), and wake after sleep onset (WASO) quantified the change from baseline given lemborexant exposure, time, and covariates, guided by consensus recommendations regarding clinical significance. A small impact of sex, body weight, and race was predicted for LPS and SE, irrespective of treatment. Effect of age on LPS was small; baseline SE was estimated to be 8% higher for a 50-year-old versus an 80-year-old, decreasing to 6% by 1 month. Baseline WASO was 13 minutes longer for Black versus White subjects, corresponding to a 5-minute lower change from baseline at the end of the study. For subjective end points, the statistically significant covariate effects for age, sex, and race were not deemed therapeutically relevant, likely reflecting physiologic sleep pattern changes across age and study subgroups. Both polysomnography and subjective analyses indicated clinically meaningful differences from baseline for both lemborexant treatments, with effects being greater for 10-mg versus 5-mg lemborexant, while indicating that covariate-specific lemborexant dose adjustments are not warranted.
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3
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Olivares MJ, Toledo C, Ortolani D, Ortiz FC, Díaz HS, Iturriaga R, Del Río R. Sleep dysregulation in sympathetic-mediated diseases: implications for disease progression. Sleep 2022; 45:6649852. [DOI: 10.1093/sleep/zsac166] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Revised: 06/18/2022] [Indexed: 11/12/2022] Open
Abstract
Abstract
The autonomic nervous system (ANS) plays an important role in the coordination of several physiological functions including sleep/wake process. Significant changes in ANS activity occur during wake-to-sleep transition maintaining the adequate cardiorespiratory regulation and brain activity. Since sleep is a complex homeostatic function, partly regulated by the ANS, it is not surprising that sleep disruption trigger and/or evidence symptoms of ANS impairment. Indeed, several studies suggest a bidirectional relationship between impaired ANS function (i.e. enhanced sympathetic drive), and the emergence/development of sleep disorders. Furthermore, several epidemiological studies described a strong association between sympathetic-mediated diseases and the development and maintenance of sleep disorders resulting in a vicious cycle with adverse outcomes and increased mortality risk. However, which and how the sleep/wake control and ANS circuitry becomes affected during the progression of ANS-related diseases remains poorly understood. Thus, understanding the physiological mechanisms underpinning sleep/wake-dependent sympathetic modulation could provide insights into diseases involving autonomic dysfunction. The purpose of this review is to explore potential neural mechanisms involved in both the onset/maintenance of sympathetic-mediated diseases (Rett syndrome, congenital central hypoventilation syndrome, obstructive sleep apnoea, type 2 diabetes, obesity, heart failure, hypertension, and neurodegenerative diseases) and their plausible contribution to the generation of sleep disorders in order to review evidence that may serve to establish a causal link between sleep disorders and heightened sympathetic activity.
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Affiliation(s)
- María José Olivares
- Department of Physiology, Laboratory of Cardiorespiratory Control, Pontificia Universidad Católica de Chile , Santiago , Chile
| | - Camilo Toledo
- Department of Physiology, Laboratory of Cardiorespiratory Control, Pontificia Universidad Católica de Chile , Santiago , Chile
- Centro de Excelencia en Biomedicina de Magallanes (CEBIMA), Universidad de Magallanes , Punta Arenas , Chile
| | - Domiziana Ortolani
- Department of Physiology, Laboratory of Cardiorespiratory Control, Pontificia Universidad Católica de Chile , Santiago , Chile
| | - Fernando C Ortiz
- Mechanisms of Myelin Formation and Repair Laboratory, Instituto de Ciencias Biomédicas, Facultad de Ciencias de la Salud, Universidad Autónoma de Chile , Santiago , Chile
| | - Hugo S Díaz
- Department of Physiology, Laboratory of Cardiorespiratory Control, Pontificia Universidad Católica de Chile , Santiago , Chile
- Centro de Excelencia en Biomedicina de Magallanes (CEBIMA), Universidad de Magallanes , Punta Arenas , Chile
| | - Rodrigo Iturriaga
- Department of Physiology, Laboratory of Cardiorespiratory Control, Pontificia Universidad Católica de Chile , Santiago , Chile
- Centro de Excelencia en Biomedicina de Magallanes (CEBIMA), Universidad de Magallanes , Punta Arenas , Chile
| | - Rodrigo Del Río
- Department of Physiology, Laboratory of Cardiorespiratory Control, Pontificia Universidad Católica de Chile , Santiago , Chile
- Centro de Excelencia en Biomedicina de Magallanes (CEBIMA), Universidad de Magallanes , Punta Arenas , Chile
- Centro de Envejecimiento y Regeneración (CARE), Pontificia Universidad Católica de Chile , Santiago , Chile
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4
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Gao XB, Horvath TL. From Molecule to Behavior: Hypocretin/orexin Revisited From a Sex-dependent Perspective. Endocr Rev 2022; 43:743-760. [PMID: 34792130 PMCID: PMC9277634 DOI: 10.1210/endrev/bnab042] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Indexed: 11/19/2022]
Abstract
The hypocretin/orexin (Hcrt/Orx) system in the perifornical lateral hypothalamus has been recognized as a critical node in a complex network of neuronal systems controlling both physiology and behavior in vertebrates. Our understanding of the Hcrt/Orx system and its array of functions and actions has grown exponentially in merely 2 decades. This review will examine the latest progress in discerning the roles played by the Hcrt/Orx system in regulating homeostatic functions and in executing instinctive and learned behaviors. Furthermore, the gaps that currently exist in our knowledge of sex-related differences in this field of study are discussed.
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Affiliation(s)
- Xiao-Bing Gao
- Department of Comparative Medicine, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Tamas L Horvath
- Department of Comparative Medicine, Yale University School of Medicine, New Haven, CT 06520, USA
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5
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Williams VM, Bhagwandin A, Swiegers J, Bertelsen MF, Hård T, Thannickal TC, Siegel JM, Sherwood CC, Manger PR. Nuclear organization of orexinergic neurons in the hypothalamus of a lar gibbon and a chimpanzee. Anat Rec (Hoboken) 2021; 305:1459-1475. [PMID: 34535040 DOI: 10.1002/ar.24775] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2021] [Revised: 07/06/2021] [Accepted: 08/17/2021] [Indexed: 11/06/2022]
Abstract
Employing orexin-A immunohistochemical staining we describe the nuclear parcellation of orexinergic neurons in the hypothalami of a lar gibbon and a chimpanzee. The clustering of orexinergic neurons within the hypothalamus and the terminal networks follow the patterns generally observed in other mammals, including laboratory rodents, strepsirrhine primates and humans. The orexinergic neurons were found within three distinct clusters in the ape hypothalamus, which include the main cluster, zona incerta cluster and optic tract cluster. In addition, the orexinergic neurons of the optic tract cluster appear to extend to a more rostral and medial location than observed in other species, being observed in the tuberal region in the anterior ventromedial aspect of the hypothalamus. While orexinergic terminal networks were observed throughout the brain, high density terminal networks were observed within the hypothalamus, medial and intralaminar nuclei of the dorsal thalamus, and within the serotonergic and noradrenergic regions of the midbrain and pons, which is typical for mammals. The expanded distribution of orexinergic neurons into the tuberal region of the ape hypothalamus, is a feature that needs to be investigated in other primate species, but appears to correlate with orexin gene expression in the same region of the human hypothalamus, but these neurons are not revealed with immunohistochemical staining in humans. Thus, it appears that apes have a broader distribution of orexinergic neurons compared to other primate species, but that the neurons within this extension of the optic tract cluster in humans, while expressing the orexin gene, do not produce the neuropeptide.
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Affiliation(s)
- Victoria M Williams
- School of Anatomical Sciences, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, Republic of South Africa
| | - Adhil Bhagwandin
- School of Anatomical Sciences, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, Republic of South Africa.,Division of Clinical Anatomy and Biological Anthropology, Department of Human Biology, University of Cape Town, Cape Town, South Africa
| | - Jordan Swiegers
- School of Anatomical Sciences, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, Republic of South Africa
| | - Mads F Bertelsen
- Centre for Zoo and Wild Animal Health, Copenhagen Zoo, Frederiksberg, Denmark
| | | | - Thomas C Thannickal
- Department of Psychiatry, School of Medicine, and Brain Research Institute, University of California, Los Angeles, Los Angeles, California, USA.,Brain Research Institute, Neurobiology Research, Sepulveda VA Medical Center, Los Angeles, California, USA
| | - Jerome M Siegel
- Department of Psychiatry, School of Medicine, and Brain Research Institute, University of California, Los Angeles, Los Angeles, California, USA.,Brain Research Institute, Neurobiology Research, Sepulveda VA Medical Center, Los Angeles, California, USA
| | - Chet C Sherwood
- Department of Anthropology and Center for the Advanced Study of Human Paleobiology, The George Washington University, Washington, District of Columbia, USA
| | - Paul R Manger
- School of Anatomical Sciences, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, Republic of South Africa
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Correa‐da‐Silva F, Fliers E, Swaab DF, Yi C. Hypothalamic neuropeptides and neurocircuitries in Prader Willi syndrome. J Neuroendocrinol 2021; 33:e12994. [PMID: 34156126 PMCID: PMC8365683 DOI: 10.1111/jne.12994] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Revised: 04/19/2021] [Accepted: 05/04/2021] [Indexed: 02/06/2023]
Abstract
Prader-Willi Syndrome (PWS) is a rare and incurable congenital neurodevelopmental disorder, resulting from the absence of expression of a group of genes on the paternally acquired chromosome 15q11-q13. Phenotypical characteristics of PWS include infantile hypotonia, short stature, incomplete pubertal development, hyperphagia and morbid obesity. Hypothalamic dysfunction in controlling body weight and food intake is a hallmark of PWS. Neuroimaging studies have demonstrated that PWS subjects have abnormal neurocircuitry engaged in the hedonic and physiological control of feeding behavior. This is translated into diminished production of hypothalamic effector peptides which are responsible for the coordination of energy homeostasis and satiety. So far, studies with animal models for PWS and with human post-mortem hypothalamic specimens demonstrated changes particularly in the infundibular and the paraventricular nuclei of the hypothalamus, both in orexigenic and anorexigenic neural populations. Moreover, many PWS patients have a severe endocrine dysfunction, e.g. central hypogonadism and/or growth hormone deficiency, which may contribute to the development of increased fat mass, especially if left untreated. Additionally, the role of non-neuronal cells, such as astrocytes and microglia in the hypothalamic dysregulation in PWS is yet to be determined. Notably, microglial activation is persistently present in non-genetic obesity. To what extent microglia, and other glial cells, are affected in PWS is poorly understood. The elucidation of the hypothalamic dysfunction in PWS could prove to be a key feature of rational therapeutic management in this syndrome. This review aims to examine the evidence for hypothalamic dysfunction, both at the neuropeptidergic and circuitry levels, and its correlation with the pathophysiology of PWS.
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Affiliation(s)
- Felipe Correa‐da‐Silva
- Department of Endocrinology and MetabolismAmsterdam Gastroenterology Endocrinology and MetabolismAmsterdam University Medical Center (UMC)University of AmsterdamAmsterdamThe Netherlands
- Laboratory of EndocrinologyAmsterdam University Medical Center (UMC)University of AmsterdamAmsterdamThe Netherlands
- Department of Neuropsychiatric DisordersNetherlands Institute for NeuroscienceAn Institute of the Royal Netherlands Academy of Arts and SciencesAmsterdamThe Netherlands
| | - Eric Fliers
- Department of Endocrinology and MetabolismAmsterdam Gastroenterology Endocrinology and MetabolismAmsterdam University Medical Center (UMC)University of AmsterdamAmsterdamThe Netherlands
| | - Dick F. Swaab
- Department of Neuropsychiatric DisordersNetherlands Institute for NeuroscienceAn Institute of the Royal Netherlands Academy of Arts and SciencesAmsterdamThe Netherlands
| | - Chun‐Xia Yi
- Department of Endocrinology and MetabolismAmsterdam Gastroenterology Endocrinology and MetabolismAmsterdam University Medical Center (UMC)University of AmsterdamAmsterdamThe Netherlands
- Laboratory of EndocrinologyAmsterdam University Medical Center (UMC)University of AmsterdamAmsterdamThe Netherlands
- Department of Neuropsychiatric DisordersNetherlands Institute for NeuroscienceAn Institute of the Royal Netherlands Academy of Arts and SciencesAmsterdamThe Netherlands
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7
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Zhao D, Zeng Z, Mo H, Hu W, Tian S, Hu D, Gong L, Hu K. Orexin-A inhibits cerebral ischaemic inflammatory injury mediated by the nuclear factor-κB signalling pathway and alleviates stroke-induced immunodepression in mice. Brain Res Bull 2021; 174:296-304. [PMID: 34216650 DOI: 10.1016/j.brainresbull.2021.06.021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2020] [Revised: 06/08/2021] [Accepted: 06/27/2021] [Indexed: 11/26/2022]
Abstract
Cerebral ischaemia is accompanied by infectious complications due to immunosuppression, known as stroke-induced immunodepression (SIID). Orexin-A (OXA), a neuropeptide produced in the hypothalamus, has been reported to have neuroprotective properties after stroke and is known to modulate inflammatory processes in peripheral tissues. The aim of this study was to determine the effects of orexin-A (OXA) on cerebral ischaemic inflammatory injury and SIID following experimental stroke. Cerebral ischaemia was induced in C57/BL6 mice by middle cerebral artery occlusion (MCAO). A mouse model of pneumonia and poststroke pneumococcal pneumonia was established by intratracheal inoculation with S. pneumoniae in a normal mouse or MCAO mouse model on the third day. We found that OXA postconditioning inhibited cerebral ischaemic inflammatory injury. The mechanism involved downregulation of the NF-κB signalling pathway. In addition, OXA may serve as a potential treatment target for attenuating stroke-induced immunodepression in mice.
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Affiliation(s)
- Dong Zhao
- Department of Respiratory and Critical Care Medicine, Renmin Hospital of Wuhan University, Zhangzhidong Road No. 99, Wuhan, 430060, China.
| | - Zhaofu Zeng
- Department of Respiratory and Critical Care Medicine, Renmin Hospital of Wuhan University, Zhangzhidong Road No. 99, Wuhan, 430060, China.
| | - Huaheng Mo
- Department of Respiratory and Critical Care Medicine, Renmin Hospital of Wuhan University, Zhangzhidong Road No. 99, Wuhan, 430060, China.
| | - Weihua Hu
- Department of Respiratory and Critical Care Medicine, Renmin Hospital of Wuhan University, Zhangzhidong Road No. 99, Wuhan, 430060, China.
| | - Sumei Tian
- Department of Respiratory and Critical Care Medicine, Renmin Hospital of Wuhan University, Zhangzhidong Road No. 99, Wuhan, 430060, China.
| | - Die Hu
- Department of Respiratory and Critical Care Medicine, Renmin Hospital of Wuhan University, Zhangzhidong Road No. 99, Wuhan, 430060, China.
| | - Lin Gong
- Department of Respiratory and Critical Care Medicine, Renmin Hospital of Wuhan University, Zhangzhidong Road No. 99, Wuhan, 430060, China.
| | - Ke Hu
- Department of Respiratory and Critical Care Medicine, Renmin Hospital of Wuhan University, Zhangzhidong Road No. 99, Wuhan, 430060, China.
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8
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Zhan D, Perrer DA, Decker AM, Langston TL, Mavanji V, Harris DL, Kotz CM, Zhang Y. Discovery of Arylsulfonamides as Dual Orexin Receptor Agonists. J Med Chem 2021; 64:8806-8825. [PMID: 34101446 PMCID: PMC8994207 DOI: 10.1021/acs.jmedchem.1c00841] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Loss of orexin-producing neurons results in narcolepsy with cataplexy, and orexin agonists have been shown to increase wakefulness and alleviate narcolepsy symptoms in animal models. Several OX2R agonists have been reported but with little or no activity at OX1R. We conducted structure-activity relationship studies on the OX2R agonist YNT-185 (2) and discovered dual agonists such as RTOXA-43 (40) with EC50's of 24 nM at both OX2R and OX1R. Computational modeling studies based on the agonist-bound OX2R cryogenic electron microscopy structures showed that 40 bound in the same binding pocket and interactions of the pyridylmethyl group of 40 with OX1R may have contributed to its high OX1R potency. Intraperitoneal injection of 40 increased time awake, decreased time asleep, and increased sleep/wake consolidation in 12-month old mice. This work provides a promising dual small molecule agonist and supports development of orexin agonists as potential treatments for orexin-deficient disorders such as narcolepsy.
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Affiliation(s)
- Dehui Zhan
- Research Triangle Institute, Research Triangle Park, North Carolina 27709
| | - David A. Perrer
- Research Triangle Institute, Research Triangle Park, North Carolina 27709
| | - Ann M. Decker
- Research Triangle Institute, Research Triangle Park, North Carolina 27709
| | | | - Vijayakumar Mavanji
- Research Service, Veterans Affairs Health Care System, Minneapolis, MN 55417
| | - Danni L. Harris
- Research Triangle Institute, Research Triangle Park, North Carolina 27709
| | - Catherine M. Kotz
- Research Service, Veterans Affairs Health Care System, Minneapolis, MN 55417
- Department of Integrative Biology and Physiology, University of Minnesota, Minneapolis, MN 55455
- Geriatric, Research, Education and Clinical Center, Minneapolis Veterans Affairs Health Care System, Minneapolis, MN 55417
| | - Yanan Zhang
- Research Triangle Institute, Research Triangle Park, North Carolina 27709
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9
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Orexin-A differentially modulates inhibitory and excitatory synaptic transmission in rat inner retina. Neuropharmacology 2021; 187:108492. [PMID: 33582153 DOI: 10.1016/j.neuropharm.2021.108492] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Revised: 01/08/2021] [Accepted: 02/06/2021] [Indexed: 11/21/2022]
Abstract
In this work, modulation by orexin-A of the release of glutamate and GABA from bipolar and amacrine cells respectively was studied by examining the effects of the neuropeptide on miniature excitatory postsynaptic currents (mEPSCs) and miniature inhibitory postsynaptic currents (mIPSCs) of rat retinal ganglion cells (GCs). Using RNAscope in situ hybridization in combination with immunohistochemistry, we showed positive signals for orexin receptor-1 (OX1R) mRNA in the bipolar cell terminals and those for orexin receptor-2 (OX2R) mRNA in the amacrine cell terminals. With whole-cell patch-clamp recordings in rat retinal slices, we demonstrated that application of orexin-A reduced the interevent interval of mEPSCs of GCs through OX1R. However, it increased the interevent interval of mIPSCs, mediated by GABAA receptors, through OX2R. Furthermore, orexin-A-induced reduction of mEPSC interevent interval was abolished by the application of PI-PLC inhibitors or PKC inhibitors. In contrast, orexin-A-induced increase of GABAergic mIPSC interevent interval was mimicked by 8-Br-cAMP or an adenylyl cyclase activator, but was eliminated by PKA antagonists. Finally, application of nimodipine, an L-type Ca2+ channel blocker, increased both mEPSC and mIPSC interevent interval, and co-application of orexin-A no longer changed the mEPSCs and mIPSCs. We conclude that orexin-A increases presynaptic glutamate release onto GCs by activating L-type Ca2+ channels in bipolar cells, a process that is mediated by an OX1R/PI-PLC/PKC signaling pathway. However, orexin-A decreases presynaptic GABA release onto GCs by inhibiting L-type Ca2+ channels in amacrine cells, a process that is mediated by an OX2R/cAMP-PKA signaling pathway.
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10
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Orexin-A Intensifies Mouse Pupillary Light Response by Modulating Intrinsically Photosensitive Retinal Ganglion Cells. J Neurosci 2021; 41:2566-2580. [PMID: 33536197 DOI: 10.1523/jneurosci.0217-20.2021] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2020] [Revised: 01/16/2021] [Accepted: 01/22/2021] [Indexed: 12/24/2022] Open
Abstract
We show for the first time that the neuropeptide orexin modulates pupillary light response, a non-image-forming visual function, in mice of either sex. Intravitreal injection of the orexin receptor (OXR) antagonist TCS1102 and orexin-A reduced and enhanced pupillary constriction in response to light, respectively. Orexin-A activated OX1Rs on M2-type intrinsically photosensitive retinal ganglion cells (M2 cells), and caused membrane depolarization of these cells by modulating inward rectifier potassium channels and nonselective cation channels, thus resulting in an increase in intrinsic excitability. The increased intrinsic excitability could account for the orexin-A-evoked increase in spontaneous discharges and light-induced spiking rates of M2 cells, leading to an intensification of pupillary constriction. Orexin-A did not alter the light response of M1 cells, which could be because of no or weak expression of OX1Rs on them, as revealed by RNAscope in situ hybridization. In sum, orexin-A is likely to decrease the pupil size of mice by influencing M2 cells, thereby improving visual performance in awake mice via enhancing the focal depth of the eye's refractive system.SIGNIFICANCE STATEMENT This study reveals the role of the neuropeptide orexin in mouse pupillary light response, a non-image-forming visual function. Intravitreal orexin-A administration intensifies light-induced pupillary constriction via increasing the excitability of M2 intrinsically photosensitive retinal ganglion cells by activating the orexin receptor subtype OX1R. Modulation of inward rectifier potassium channels and nonselective cation channels were both involved in the ionic mechanisms underlying such intensification. Orexin could improve visual performance in awake mice by reducing the pupil size and thereby enhancing the focal depth of the eye's refractive system.
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11
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Amodeo LR, Wills DN, Sanchez-Alavez M, Ehlers CL. Effects of an Orexin-2 Receptor Antagonist on Sleep and Event-Related Oscillations in Female Rats Exposed to Chronic Intermittent Ethanol During Adolescence. Alcohol Clin Exp Res 2020; 44:1378-1388. [PMID: 32424852 DOI: 10.1111/acer.14361] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Accepted: 05/05/2020] [Indexed: 12/25/2022]
Abstract
BACKGROUND Alcohol use is on the rise among women in the United States which is especially concerning since women who drink have a higher risk of alcohol-related problems. Orexin (hypocretin) receptor antagonists may have some therapeutic value for alcohol-induced insomnia; however, the use of this class of drugs following female adolescent binge drinking is limited. The current study will address whether adolescent intermittent ethanol (AIE) in female rats can result in lasting changes in sleep pathology and whether orexin-targeted treatment can alleviate these deficits. METHODS Following a 5-week AIE vapor model, young adult rats were evaluated on waking event-related oscillations (EROs) and EEG sleep. Subsequently, AIE rats were treated with orexin receptor 2 (OX2 R) antagonist (MK-1064; 10, 20mg/kg) to test for modifications in sleep pathology and waking ERO. RESULTS Female AIE rats exhibited lasting changes in sleep compared to controls. This was demonstrated by increased fragmentation of slow wave sleep (SWS) and rapid eye movement sleep, as well as reductions in delta and theta power during SWS. There was no impact of AIE on waking EROs. Acute MK-1064 hastened SWS onset and increased the number of SWS episodes, without increasing sleep fragmentation in AIE and controls. While treatment with MK-1064 did not impact sleep EEG spectra, waking ERO energy was increased in delta, theta, and beta frequency bands. CONCLUSIONS These results demonstrate that AIE can produce lasting changes in sleep in female rats, highly similar to what we previously found in males. Additionally, while the OX2 R antagonist promoted sleep in both alcohol-exposed and unexposed rats, it did not reverse most of the alcohol-induced disruptions in sleep. Thus, OX2 R antagonism may serve as a potential therapeutic strategy for the treatment of insomnia, but not the specific signs of alcohol-induced insomnia.
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Affiliation(s)
- Leslie R Amodeo
- From the, Department of Psychology, (LRA), California State University San Bernardino, San Bernardino, California
| | - Derek N Wills
- Department of Neuroscience, (DNW, MS-A, CLE), The Scripps Research Institute, La Jolla, California
| | - Manuel Sanchez-Alavez
- Department of Neuroscience, (DNW, MS-A, CLE), The Scripps Research Institute, La Jolla, California
| | - Cindy L Ehlers
- Department of Neuroscience, (DNW, MS-A, CLE), The Scripps Research Institute, La Jolla, California
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12
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Freeman LR, Aston-Jones G. Activation of medial hypothalamic orexin neurons during a Go/No-Go task. Brain Res 2020; 1731:145928. [PMID: 30176242 PMCID: PMC6395540 DOI: 10.1016/j.brainres.2018.08.031] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2018] [Revised: 08/22/2018] [Accepted: 08/28/2018] [Indexed: 11/30/2022]
Abstract
Orexin neurons (Orx; also referred to as hypocretin) are found exclusively in the hypothalamus, and release the neuropeptides orexin A and orexin B (also referred to as hypocretin 1 and 2) throughout the CNS. With its widespread targets, the orexin system is involved in a number of functions including, but not limited to stress, reward, wakefulness, and food seeking. Our laboratory has previously proposed that the dorsomedial hypothalamus (DMH) and perifornical (PFA) orexin neurons function in stress and arousal whereas those in lateral hypothalamus (LH) participate in reward processes (Harris and Aston-Jones, 2006). In the current study, we compared Fos activation in orexin neurons located in medial hypothalamus (DMH and PFA) to those in LH during a Go/No-Go task for a highly palatable food reward, a task that would likely activate regions for arousal/attention as well as reward. The Go/No-Go paradigm is a useful behavioral tool to measure behavioral inhibition, impulsivity, learning, and reaction time. Our results revealed increased activation of medial hypothalamic orexin neurons correlated with greater accuracy on the Go/No-Go task. No correlation was found between Go/No-Go accuracy and activation of lateral hypothalamic orexin neurons. This study supports a functional dichotomy of medial vs lateral orexin neurons, and indicates a role for medial orexin neurons in behavioral performance that requires response inhibition.
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Affiliation(s)
- Linnea R Freeman
- Department of Neurosciences, Medical University of South Carolina, Charleston, SC 29425, United States; Department of Biology, Furman University, Greenville, SC 29613, United States.
| | - Gary Aston-Jones
- Department of Neurosciences, Medical University of South Carolina, Charleston, SC 29425, United States; Brain Health Institute, Rutgers University/Rutgers Biomedical and Health Sciences, Piscataway, NJ 08854, United States
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Zarrabian S, Riahi E, Karimi S, Razavi Y, Haghparast A. The potential role of the orexin reward system in future treatments for opioid drug abuse. Brain Res 2020; 1731:146028. [DOI: 10.1016/j.brainres.2018.11.023] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Revised: 11/11/2018] [Accepted: 11/15/2018] [Indexed: 12/20/2022]
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14
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Firouzabadi N, Navabzadeh N, Moghimi-Sarani E, Haghnegahdar M. Orexin/Hypocretin Type 2 Receptor (HCRTR2) Gene as a Candidate Gene in Sertraline-Associated Insomnia in Depressed Patients. Neuropsychiatr Dis Treat 2020; 16:1121-1128. [PMID: 32440126 PMCID: PMC7210038 DOI: 10.2147/ndt.s250141] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Accepted: 04/22/2020] [Indexed: 11/23/2022] Open
Abstract
BACKGROUND Selective serotonin reuptake inhibitors (SSRIs) are considered as first-line drugs for treating depressive disorders. Among the adverse effects reported with sertraline is sleep disturbances; however, the etiology lying beneath is obscure. Orexin, the most recently discovered neurotransmitter, is involved in the sleep cycle. It exerts its physiological actions through orexin or hypocretin type 1 and 2 receptors (HCRTR1 and HCRTR2). Dysfunction of the orexin system contributes to various psychiatric, neurologic and neuropsychiatric disorders. Thus, our study aimed to assess the possible association of genetic variation of HCRTR2 G1246A with hypersomnia reported with sertraline in a group of major depressive disorder (MDD) patients. PATIENTS AND METHODS Ninety-six newly diagnosed MDD patients were enrolled in our cohort study. MDD was assessed using DSM-V criteria. Insomnia Severity Index (ISI) was used to assess insomnia at baseline (week 0) and week 4. Blood samples were collected for further genotyping of HCRTR2 G1246A (rs2653349) using polymerase chain reaction-restriction fragment length polymorphism. RESULTS A significant association between G1264A polymorphism of HCRTR2 and insomnia was observed. Insomnia with sertraline happens by 2.5-fold (P=0.022; odds ratio (OR)=2.5; 95% confidence interval (CI): 1.1-5.7) in patients having GG genotype. Patients with G allele experience insomnia by 2.1-fold more than A allele carriers (P=0.022; OR=2.1; 95% CI= 1.1-4.0). Subgroup analysis showed a significant association between GG genotype as well as the G allele and insomnia only in female MDD patients (P=0.011; OR=4.0; 95% CI=1.3-12.0 and P=0.033; OR=2.4; 95% CI=1.02-5.7, respectively). CONCLUSION In conclusion, the G1246A variant might be a predictor for insomnia in MDD patients treated with sertraline. Our findings support the idea that some variants of the HCRTR might contribute to inter-individual variability in the sleep pattern of patients receiving antidepressants.
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Affiliation(s)
- Negar Firouzabadi
- Department of Pharmacology and Toxicology, School of Pharmacy, Shiraz University of Medical Sciences, Shiraz, Iran.,Pharmaceutical Sciences Research Center, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Niloofar Navabzadeh
- Department of Pharmacology and Toxicology, School of Pharmacy, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Ebrahim Moghimi-Sarani
- Department of Psychiatry, School of Medicine, Shiraz University of Medical Sciences, School of Medicine, Shiraz, Iran
| | - Maral Haghnegahdar
- Department of Pharmacology and Toxicology, School of Pharmacy, Shiraz University of Medical Sciences, Shiraz, Iran
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Barateau L, Lopez R, Dauvilliers Y. Clinical neurophysiology of CNS hypersomnias. HANDBOOK OF CLINICAL NEUROLOGY 2019; 161:353-367. [PMID: 31307613 DOI: 10.1016/b978-0-444-64142-7.00060-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
Abstract
Central nervous system hypersomnias (narcolepsy type 1 and type 2, idiopathic hypersomnia, and Kleine-Levin syndrome) are orphan sleep disorders in which the predominant symptom is excessive daytime sleepiness. The evaluation of sleepiness requires rigorous clinical and neurophysiologic approaches that may include the Epworth Sleepiness Scale, multiple sleep latency tests, and the maintenance of wakefulness test. However, to date, no gold standard measurement of excessive sleepiness exists, and there are no quantifiable biologic markers. The main pathophysiologic feature of central hypersomnias is thought to reflect a deficiency of arousal systems, rather than an overactivity of sleep systems or an imbalance between those systems. Impaired neurotransmission of hypocretin/orexin (neuropeptides of the lateral hypothalamus) is involved in the neurobiology of narcolepsy with cataplexy (NT1). NT1 is a well-characterized disorder, due to the destruction of hypocretin/orexin neurons by a probable autoimmune process. The biologic hallmarks of the other central hypersomnias remain unknown, and neurophysiologic biomarkers are still of major importance for the diagnosis and characterization of those disorders.
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Affiliation(s)
- Lucie Barateau
- Department of Neurology, Sleep-Wake Disorders Center, Hôpital Gui-de-Chauliac, Montpellier, France; National Reference Network for Narcolepsy, Montpellier, France
| | - Régis Lopez
- Department of Neurology, Sleep-Wake Disorders Center, Hôpital Gui-de-Chauliac, Montpellier, France; National Reference Network for Narcolepsy, Montpellier, France
| | - Yves Dauvilliers
- Department of Neurology, Sleep-Wake Disorders Center, Hôpital Gui-de-Chauliac, Montpellier, France; National Reference Network for Narcolepsy, Montpellier, France.
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16
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Hypocretin and the Regulation of Sleep-Wake Transitions. ACTA ACUST UNITED AC 2019. [DOI: 10.1016/b978-0-12-813743-7.00006-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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17
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Orexinergic neurons are involved in the chemosensory control of breathing during the dark phase in a Parkinson's disease model. Exp Neurol 2018; 309:107-118. [PMID: 30110606 DOI: 10.1016/j.expneurol.2018.08.004] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2018] [Revised: 08/02/2018] [Accepted: 08/11/2018] [Indexed: 02/07/2023]
Abstract
Parkinson's disease (PD) is a neurodegenerative disorder characterized by loss of dopaminergic neurons in the substantia nigra compacta (SNpc) and the only risk factor is aging. We showed that in 6-hydroxydopamine (6-OHDA)-model of PD there is a reduction in the neuronal profile within the brainstem ventral respiratory column with a decrease in the hypercapnic ventilatory response. Here we tested the involvement of orexin cells from the lateral hypothalamus/perifornical area (LH/PeF) on breathing in a 6-OHDA PD model. In this model of PD, there is a reduction in the total number of orexinergic neurons and in the number of orexinergic neurons that project to the RTN, without changing the number of CO2-activated orexinergic neurons during the dark phase. The ventilation at rest and in response to hypercapnia (7% CO2) was assessed in animals that received 6-OHDA or vehicle injections into the striatum and saporin anti-Orexin-B or IgG saporin into the LH/PeF during the sleep and awake states. The experiments showed a reduction of respiratory frequency (fR) at rest during the light phase in PD animals only during sleep. During the dark phase, there was an impaired fR response to hypercapnia in PD animals with depletion of orexinergic neurons in awake and sleeping rats. In conclusion, the degeneration of orexinergic neurons in this model of PD can be related to impaired chemoreceptor function in the dark phase.
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18
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Wang C, Wang Q, Ji B, Pan Y, Xu C, Cheng B, Bai B, Chen J. The Orexin/Receptor System: Molecular Mechanism and Therapeutic Potential for Neurological Diseases. Front Mol Neurosci 2018; 11:220. [PMID: 30002617 PMCID: PMC6031739 DOI: 10.3389/fnmol.2018.00220] [Citation(s) in RCA: 113] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2018] [Accepted: 06/06/2018] [Indexed: 12/25/2022] Open
Abstract
Orexins, also known as hypocretins, are two neuropeptides secreted from orexin-containing neurons, mainly in the lateral hypothalamus (LH). Orexins orchestrate their effects by binding and activating two G-protein–coupled receptors (GPCRs), orexin receptor type 1 (OX1R) and type 2 (OX2R). Orexin/receptor pathways play vital regulatory roles in many physiological processes, especially feeding behavior, sleep–wake rhythm, reward and addiction and energy balance. Furthermore several reports showed that orexin/receptor pathways are involved in pathological processes of neurological diseases such as narcolepsy, depression, ischemic stroke, drug addiction and Alzheimer’s disease (AD). This review article summarizes the expression patterns, physiological functions and potential molecular mechanisms of the orexin/receptor system in neurological diseases, providing an overall framework for considering these pathways from the standpoints of basic research and clinical treatment of neurological diseases.
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Affiliation(s)
- Chunmei Wang
- Neurobiology Key Laboratory of Jining Medical University in Colleges of Shandong, Jining Medical University, Jining, China
| | - Qinqin Wang
- Neurobiology Key Laboratory of Jining Medical University in Colleges of Shandong, Jining Medical University, Jining, China
| | - Bingyuan Ji
- Neurobiology Key Laboratory of Jining Medical University in Colleges of Shandong, Jining Medical University, Jining, China
| | - Yanyou Pan
- Neurobiology Key Laboratory of Jining Medical University in Colleges of Shandong, Jining Medical University, Jining, China
| | - Chao Xu
- Neurobiology Key Laboratory of Jining Medical University in Colleges of Shandong, Jining Medical University, Jining, China
| | - Baohua Cheng
- Neurobiology Key Laboratory of Jining Medical University in Colleges of Shandong, Jining Medical University, Jining, China
| | - Bo Bai
- Neurobiology Key Laboratory of Jining Medical University in Colleges of Shandong, Jining Medical University, Jining, China
| | - Jing Chen
- Neurobiology Key Laboratory of Jining Medical University in Colleges of Shandong, Jining Medical University, Jining, China.,Division of Biomedical Sciences, Warwick Medical School, University of Warwick, Coventry, United Kingdom
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Tyree SM, Borniger JC, de Lecea L. Hypocretin as a Hub for Arousal and Motivation. Front Neurol 2018; 9:413. [PMID: 29928253 PMCID: PMC5997825 DOI: 10.3389/fneur.2018.00413] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2018] [Accepted: 05/18/2018] [Indexed: 01/01/2023] Open
Abstract
The lateral hypothalamus is comprised of a heterogeneous mix of neurons that serve to integrate and regulate sleep, feeding, stress, energy balance, reward, and motivated behavior. Within these populations, the hypocretin/orexin neurons are among the most well studied. Here, we provide an overview on how these neurons act as a central hub integrating sensory and physiological information to tune arousal and motivated behavior accordingly. We give special attention to their role in sleep-wake states and conditions of hyper-arousal, as is the case with stress-induced anxiety. We further discuss their roles in feeding, drug-seeking, and sexual behavior, which are all dependent on the motivational state of the animal. We further emphasize the application of powerful techniques, such as optogenetics, chemogenetics, and fiber photometry, to delineate the role these neurons play in lateral hypothalamic functions.
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Affiliation(s)
- Susan M Tyree
- Department of Psychiatry and Behavioral Sciences, Stanford University, Stanford, CA, United States
| | - Jeremy C Borniger
- Department of Psychiatry and Behavioral Sciences, Stanford University, Stanford, CA, United States
| | - Luis de Lecea
- Department of Psychiatry and Behavioral Sciences, Stanford University, Stanford, CA, United States
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20
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Chen L, Liu C, Ye Z, Wang B, He S. Assessment of sleep quality using cardiopulmonary coupling analysis in patients with Parkinson's disease. Brain Behav 2018; 8:e00970. [PMID: 29761019 PMCID: PMC5943733 DOI: 10.1002/brb3.970] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/21/2017] [Revised: 02/21/2018] [Accepted: 03/11/2018] [Indexed: 11/25/2022] Open
Abstract
Objectives To assess the sleep quality of patients with Parkinson's disease (PD) and evaluate the effect of cardiopulmonary coupling (CPC) analysis on sleep quality and its correlation with subjective complaints in patients with PD. Methods Our study included 42 patients with PD and 30 healthy controls. CPC analysis and the Pittsburgh Sleep Quality Index (PSQI) were used to evaluate the sleep quality of subjects. Results High-frequency coupling (HFC) and sleep efficiency were significantly lower in the PD than in the control group, whereas very low-frequency coupling (VLFC) and sleep latency were significantly higher in the PD than in the control group. PSQI scores were significantly higher in the PD than in the control group (all p < .05). The PSQI score showed a negative correlation with the HFC ratio in the PD group (r = -.478, p = .001). Factors related to the occurrence of PD with poor sleep quality were the unified Parkinson's disease rating scale (UPDRS) score and nocturia. Conclusions The sleep quality of patients with PD was generally decreased. CPC analysis can reflect the subjective sleep quality of patients with PD and serve as an effective sleep monitoring tool.
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Affiliation(s)
- Lindi Chen
- Department of NeurologyZhoushan HospitalWenzhou Medical UniversityZhoushanChina
| | - Chunyan Liu
- Department of Critical Care MedicineHuzhou Central HospitalHuzhouChina
| | - Zhinan Ye
- Department of NeurologyTaizhou Municipal HospitalTaizhouChina
| | - Binda Wang
- Department of NeurologyZhoushan HospitalWenzhou Medical UniversityZhoushanChina
| | - Songbin He
- Department of NeurologyZhoushan HospitalWenzhou Medical UniversityZhoushanChina
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21
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Eban-Rothschild A, Appelbaum L, de Lecea L. Neuronal Mechanisms for Sleep/Wake Regulation and Modulatory Drive. Neuropsychopharmacology 2018; 43:937-952. [PMID: 29206811 PMCID: PMC5854814 DOI: 10.1038/npp.2017.294] [Citation(s) in RCA: 125] [Impact Index Per Article: 20.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/15/2017] [Revised: 11/17/2017] [Accepted: 11/24/2017] [Indexed: 12/17/2022]
Abstract
Humans have been fascinated by sleep for millennia. After almost a century of scientific interrogation, significant progress has been made in understanding the neuronal regulation and functions of sleep. The application of new methods in neuroscience that enable the analysis of genetically defined neuronal circuits with unprecedented specificity and precision has been paramount in this endeavor. In this review, we first discuss electrophysiological and behavioral features of sleep/wake states and the principal neuronal populations involved in their regulation. Next, we describe the main modulatory drives of sleep and wakefulness, including homeostatic, circadian, and motivational processes. Finally, we describe a revised integrative model for sleep/wake regulation.
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Affiliation(s)
| | - Lior Appelbaum
- The Faculty of Life Sciences and the Multidisciplinary Brain Research Center, Bar-Ilan University, Ramat-Gan, Israel
| | - Luis de Lecea
- Department of Psychiatry and Behavioral Sciences, Stanford University, Stanford, CA, USA
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22
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Orexin-B modulates synaptic transmission of rod bipolar cells in rat retina. Neuropharmacology 2018; 133:38-50. [PMID: 29325900 DOI: 10.1016/j.neuropharm.2018.01.007] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2017] [Revised: 12/31/2017] [Accepted: 01/04/2018] [Indexed: 12/16/2022]
Abstract
Orexin-A, -B play a crucial role in arousal and feeding by activating two G-protein-coupled receptors: orexin receptor 1 (OX1R) and orexin receptor 2 (OX2R). Orexins, along with orexin receptors, are expressed in retinal neurons, and they have been shown to differentially modulate excitatory AMPA receptors of amacrine and ganglion cells in the inner retina. In this work we report that orexin-B modulates the activity of rod bipolar cells (RBCs) located in the outer retina of rat. Intravitreal injection of orexin-B increased the amplitude of the scotopic electroretinographic b-wave, a reflection of RBC activity, recorded in vivo. Patch clamp recordings in rat retinal slices showed that orexin-B did not change glutamatergic excitatory component of the RBC response driven by photoreceptors. Effects of orexin-B on GABA receptor-mediated synaptic transmission of RBCs were then examined. In retinal slice preparations orexin-B suppressed GABA receptor-mediated inhibitory postsynaptic currents of RBCs in the inner plexiform layer. Furthermore, using whole-cell recordings in isolated RBCs it was shown that orexin-B suppressed GABAC receptor-, but not GABAA receptor-, mediated currents of the RBCs, an effect that was blocked by OX1R and OX2R antagonists. The orexin-B-induced inhibition of GABAC currents was likely mediated by a Gi/o/PC-PLC/Ca2+-independent PKC signaling pathway, as such inhibition was absent when each step of the above-pathway was blocked with GDP-β-S/pertussis toxin (for Gi/o), D609 (for PLC), bisindolylmaleimide IV (for PKC)/rottlerin (for PKCδ), respectively. The orexin-B-induced potentiation of RBC activity may improve visual acuity and contrast sensitivity of the animal during the dark period (wake phase).
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Checa-Ros A, Muñoz-Hoyos A, Molina-Carballo A, Muñoz-Gallego A, Narbona-Galdó S, Jerez-Calero A, Augustín-Morales MDC. Analysis of Different Melatonin Secretion Patterns in Children With Sleep Disorders: Melatonin Secretion Patterns in Children. J Child Neurol 2017; 32:1000-1008. [PMID: 28911277 DOI: 10.1177/0883073817726680] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The objective of this study was to analyze circadian patterns of urinary 6-sulphatoxymelatonin (aMT6s) excretion in children with primary sleep disorders in comparison with healthy controls. A total of 124 control children and 124 patients (aged 4-14 years) diagnosed with diverse primary sleep disorders were recruited. aMT6s concentrations were measured in diurnal and nocturnal urine, as well as in 24-hour urine. aMT6s levels were significantly higher and showed significantly more evident circadian variations in the control group ( P < .001). Four different melatonin (aMT) production and excretion patterns were distinguished in the group with sleep disorders: (1) standard aMT production pattern, (2) low aMT production pattern, (3) aMT production pattern with absence of circadian variation, and (4) aMT hyperproduction pattern. This study highlights the importance of analyzing specific alterations of aMT secretion in each sleep disorder and provides evidences to explain why not all children with sleep disturbances do respond to aMT treatment.
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Affiliation(s)
- Ana Checa-Ros
- 1 San Cecilio University Hospital, Department of Pediatrics, School of Medicine, University of Granada, Spain
| | - Antonio Muñoz-Hoyos
- 1 San Cecilio University Hospital, Department of Pediatrics, School of Medicine, University of Granada, Spain
| | - Antonio Molina-Carballo
- 1 San Cecilio University Hospital, Department of Pediatrics, School of Medicine, University of Granada, Spain
| | | | - Susana Narbona-Galdó
- 1 San Cecilio University Hospital, Department of Pediatrics, School of Medicine, University of Granada, Spain
| | - Antonio Jerez-Calero
- 1 San Cecilio University Hospital, Department of Pediatrics, School of Medicine, University of Granada, Spain
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Hall S, Deurveilher S, Ko KR, Burns J, Semba K. Region-specific increases in FosB/ΔFosB immunoreactivity in the rat brain in response to chronic sleep restriction. Behav Brain Res 2017; 322:9-17. [PMID: 28089853 DOI: 10.1016/j.bbr.2017.01.024] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2016] [Revised: 01/05/2017] [Accepted: 01/11/2017] [Indexed: 01/23/2023]
Abstract
Using a rat model of chronic sleep restriction (CSR) featuring periodic sleep deprivation with slowly rotating wheels (3h on/1h off), we previously observed that 99h of this protocol induced both homeostatic and allostatic (adaptive) changes in physiological and behavioural measures. Notably, the initial changes in sleep intensity and attention performance gradually adapted during CSR despite accumulating sleep loss. To identify brain regions involved in these responses, we used FosB/ΔFosB immunohistochemistry as a marker of chronic neuronal activation. Adult male rats were housed in motorized activity wheels and underwent the 3/1 CSR protocol for 99h, or 99h followed by 6 or 12days of recovery. Control rats were housed in home cages, locked activity wheels, or unlocked activity wheels that the animals could turn freely. Immunohistochemistry was conducted using an antibody that recognized both FosB and ΔFosB, and 24 brain regions involved in sleep/wake, autonomic, and limbic functions were examined. The number of darkly-stained FosB/ΔFosB-immunoreactive cells was increased immediately following 99h of CSR in 8/24 brain regions, including the medial preoptic and perifornical lateral hypothalamic areas, dorsomedial and paraventricular hypothalamic nuclei, and paraventricular thalamic nucleus. FosB/ΔFosB labeling was at control levels in all 8 brain areas following 6 or 12 recovery days, suggesting that most of the immunoreactivity immediately after CSR reflected FosB, the more transient marker of chronic neuronal activation. This region-specific induction of FosB/ΔFosB following CSR may be involved in the mechanisms underlying the allostatic changes in behavioural and physiological responses to CSR.
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Affiliation(s)
- Shannon Hall
- Department of Medical Neuroscience, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Samüel Deurveilher
- Department of Medical Neuroscience, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Kristin Robin Ko
- School of Biomedical Engineering, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Joan Burns
- Department of Medical Neuroscience, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Kazue Semba
- Department of Medical Neuroscience, Dalhousie University, Halifax, Nova Scotia, Canada; Department of Psychology & Neuroscience, Dalhousie University, Halifax, Nova Scotia, Canada; Department of Psychiatry, Dalhousie University, Halifax, Nova Scotia, Canada.
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Tanaka S, Takizawa N, Honda Y, Koike T, Oe S, Toyoda H, Kodama T, Yamada H. Hypocretin/orexin loss changes the hypothalamic immune response. Brain Behav Immun 2016; 57:58-67. [PMID: 27318095 DOI: 10.1016/j.bbi.2016.06.009] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/28/2016] [Revised: 06/13/2016] [Accepted: 06/14/2016] [Indexed: 12/26/2022] Open
Abstract
Hypocretin, also known as orexin, maintains the vigilance state and regulates various physiological processes, such as arousal, sleep, food intake, energy expenditure, and reward. Previously, we found that when wild-type mice and hypocretin/ataxin-3 littermates (which are depleted of hypothalamic hypocretin-expressing neurons postnatally) were administered lipopolysaccharide (LPS), the two genotypes exhibited significant differences in their sleep/wake cycle, including differences in the degree of increase in sleep periods and in recovery from sickness behaviour. In the present study, we examined changes in the hypothalamic vigilance system and in the hypothalamic expression of inflammatory factors in response to LPS in hypocretin/ataxin-3 mice. Peripheral immune challenge with LPS affected the hypothalamic immune response and vigilance states. This response was altered by the loss of hypocretin. Hypocretin expression was inhibited after LPS injection in both hypocretin/ataxin-3 mice and their wild-type littermates, but expression was completely abolished only in hypocretin/ataxin-3 mice. Increases in the number of histidine decarboxylase (HDC)-positive cells and in Hdc mRNA expression were found in hypocretin/ataxin-3 mice, and this increase was suppressed by LPS. Hypocretin loss did not impact the change in expression of hypothalamic inflammatory factors in response to LPS, except for interferon gamma and colony stimulating factor 3. The number of c-Fos-positive/HDC-positive cells in hypocretin/ataxin-3 mice administered LPS injections was elevated, even during the rest period, in all areas, suggesting that there is an increase in the activity of histaminergic neurons in hypocretin/ataxin-3 mice following LPS injection. Taken together, our results suggest a novel role for hypocretin in the hypothalamic response to peripheral immune challenge. Our findings contribute to the understanding of the pathophysiology of narcolepsy.
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Affiliation(s)
- Susumu Tanaka
- Department of Anatomy and Cell Science, Kansai Medical University, Hirakata, Japan; SLEEP Disorders Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan.
| | - Nae Takizawa
- Department of Anatomy and Cell Science, Kansai Medical University, Hirakata, Japan
| | - Yoshiko Honda
- SLEEP Disorders Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
| | - Taro Koike
- Department of Anatomy and Cell Science, Kansai Medical University, Hirakata, Japan
| | - Souichi Oe
- Department of Anatomy and Cell Science, Kansai Medical University, Hirakata, Japan
| | - Hiromi Toyoda
- SLEEP Disorders Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan; Department of Human Genetics, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Tohru Kodama
- SLEEP Disorders Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
| | - Hisao Yamada
- Department of Anatomy and Cell Science, Kansai Medical University, Hirakata, Japan
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26
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Decreased sleep stage transition pattern complexity in narcolepsy type 1. Clin Neurophysiol 2016; 127:2812-2819. [DOI: 10.1016/j.clinph.2016.05.364] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2016] [Revised: 05/09/2016] [Accepted: 05/31/2016] [Indexed: 11/19/2022]
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Liu F, Weng SJ, Yang XL, Zhong YM. Orexin-A potentiates L-type calcium/barium currents in rat retinal ganglion cells. Neuroscience 2015; 305:225-37. [PMID: 26259903 DOI: 10.1016/j.neuroscience.2015.08.008] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2015] [Revised: 07/27/2015] [Accepted: 08/04/2015] [Indexed: 01/07/2023]
Abstract
Two neuropeptides, orexin-A and orexin-B (also called hypocretin-1 and -2), have been implicated in sleep/wake regulation, feeding behaviors via the activation of two subtypes of G-protein-coupled receptors: orexin 1 and orexin 2 receptors (OX1R and OX2R). While the expression of orexins and orexin receptors is immunohistochemically revealed in retinal neurons, the function of these peptides in the retina is largely unknown. Using whole-cell patch-clamp recordings in rat retinal slices, we demonstrated that orexin-A increased L-type-like barium currents (IBa,L) in ganglion cells (GCs), and the effect was blocked by the selective OX1R antagonist SB334867, but not by the OX2R antagonist TCS OX2 29. The orexin-A effect was abolished by intracellular dialysis of GDP-β-S/GPAnt-2A, a Gq protein inhibitor, suggesting the mediation of Gq. Additionally, during internal dialysis of the phosphatidylinositol (PI)-phospholipase C (PLC) inhibitor U73122, orexin-A did not change the IBa,L of GCs, whereas the orexin-A effect persisted in the presence of the phosphatidylcholine (PC)-PLC inhibitor D609. The orexin-A-induced potentiation was not seen with internal infusion of Ca(2+)-free solution or when inositol 1,4,5-trisphosphate (IP3)-sensitive Ca(2+) release from intracellular stores was blocked by heparin/xestospongins-C. Moreover, the orexin-A effect was mimicked by the protein kinase C (PKC) activator phorbol 12-myristate 13-acetate, but was eliminated when PKC was inhibited by bisindolylmaleimide IV (Bis-IV)/Gö6976. Neither adenosine 3',5'-cyclic monophosphate (cAMP)-protein kinase A (PKA) nor guanosine 3',5'-cyclic monophosphate (cGMP)-protein kinase G (PKG) signaling pathway was likely involved, as orexin-A persisted to potentiate the IBa,L of GCs no matter these two pathways were activated or inhibited. These results suggest that, by activating OX1R, orexin-A potentiates the IBa,L of rat GCs through a distinct Gq/PI-PLC/IP3/Ca(2+)/PKC signaling pathway.
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Affiliation(s)
- F Liu
- Institute of Neurobiology, State Key Laboratory of Medical Neurobiology, Institutes of Brain Science and Collaborative Innovation Center for Brain Science, Fudan University, 138 Yixueyuan Road, Shanghai 200032, China
| | - S-J Weng
- Institute of Neurobiology, State Key Laboratory of Medical Neurobiology, Institutes of Brain Science and Collaborative Innovation Center for Brain Science, Fudan University, 138 Yixueyuan Road, Shanghai 200032, China
| | - X-L Yang
- Institute of Neurobiology, State Key Laboratory of Medical Neurobiology, Institutes of Brain Science and Collaborative Innovation Center for Brain Science, Fudan University, 138 Yixueyuan Road, Shanghai 200032, China
| | - Y-M Zhong
- Institute of Neurobiology, State Key Laboratory of Medical Neurobiology, Institutes of Brain Science and Collaborative Innovation Center for Brain Science, Fudan University, 138 Yixueyuan Road, Shanghai 200032, China.
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Tanaka S, Toyoda H, Honda Y, Seki Y, Sakurai T, Honda K, Kodama T. Hypocretin/orexin prevents recovery from sickness. Biomed Rep 2015; 3:648-650. [PMID: 26405539 DOI: 10.3892/br.2015.491] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2015] [Accepted: 06/18/2015] [Indexed: 02/02/2023] Open
Abstract
Sickness behavior is defined as states of lethargy, depression, anxiety, loss of appetite, hypersomnia, hyperalgesia, reduction of grooming and failure to concentrate that can be induced by inflammatory diseases, such as infections and cancer. Recent findings revealed that the lipopolysaccharide (LPS) injection causes lethargy as a consequence of the inhibition of hypocretin signaling. The hypocretin system maintains the vigilance state in various physiological processes. In order to investigate the sleep arousal system against sickness behavior, LPS-induced sickness behavior was examined in hypocretin-ataxin-3 transgenic mice, whose hypocretin neurons were postnatally ablated. Sleep-wake activity was determined following the administration of LPS at Zeitgeber time (ZT) 8.0 in ataxin-3 transgenic mice, and the age-, gender-matched wild-type littermates. LPS injection induced increases in non-rapid eye movement (REM) sleep in the matched wild-type littermates. In addition, a further increase in periods of sleep according to the loss of hypocretin neurons was identified in the ataxin-3 transgenic mice. A marked reduction of awakening during ZT12-ZT18 was observed as expected following LPS injection in the mouse lines. The increase in the period of non-REM sleep was not observed on the next day following LPS administration in either of the mouse lines. Complete recovery of physical activity was not observed in the matched wild-type littermates. Ataxin-3 transgenic mice recovered their physical activity to the same level as that on the first day before LPS administration. These results suggest the possibility that a faster recovery is the result of deeper resting according to the absence of hypocretin neurons, as ataxin-3 transgenic mice demonstrated more non-REM sleep.
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Affiliation(s)
- Susumu Tanaka
- Sleep Disorders Project, Department of Psychiatry and Behavioral Science, Tokyo Metropolitan Institute of Medical Science, Tokyo 156-8506, Japan ; Department of Anatomy and Cell Science, Kansai Medical University, Hirakata, Osaka 573-1010, Japan
| | - Hiromi Toyoda
- Sleep Disorders Project, Department of Psychiatry and Behavioral Science, Tokyo Metropolitan Institute of Medical Science, Tokyo 156-8506, Japan ; Department of Human Genetics, Graduate School of Medicine, The University of Tokyo, Tokyo 113-0033, Japan
| | - Yoshiko Honda
- Sleep Disorders Project, Department of Psychiatry and Behavioral Science, Tokyo Metropolitan Institute of Medical Science, Tokyo 156-8506, Japan
| | - Yasuko Seki
- Sleep Disorders Project, Department of Psychiatry and Behavioral Science, Tokyo Metropolitan Institute of Medical Science, Tokyo 156-8506, Japan
| | - Takeshi Sakurai
- Department of Molecular Neuroscience and Integrative Physiology, Faculty of Medicine, Kanazawa University, Kanazawa, Ishikawa 920-8640, Japan ; International Institute for Integrative Sleep Medicine, University of Tsukuba, Tsukuba, Ibaraki 305-8577, Japan
| | - Kazuki Honda
- Sleep Disorders Project, Department of Psychiatry and Behavioral Science, Tokyo Metropolitan Institute of Medical Science, Tokyo 156-8506, Japan
| | - Tohru Kodama
- Sleep Disorders Project, Department of Psychiatry and Behavioral Science, Tokyo Metropolitan Institute of Medical Science, Tokyo 156-8506, Japan
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29
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Narcolepsia-cataplejía, una enfermedad de etiología autoinmune. An Pediatr (Barc) 2015; 82:271-2. [DOI: 10.1016/j.anpedi.2014.10.026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2014] [Revised: 09/24/2014] [Accepted: 10/24/2014] [Indexed: 11/21/2022] Open
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Navarro-Abia V, Pedrera-Mazarro A, Bélanger-Quintana A, Aparicio-Meix J. Narcolepsy-cataplexy, a disease of autoimmune origin. ANALES DE PEDIATRÍA (ENGLISH EDITION) 2015. [DOI: 10.1016/j.anpede.2015.03.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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31
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Zheng C, Deng QQ, Liu LL, Wang MY, Zhang G, Sheng WL, Weng SJ, Yang XL, Zhong YM. Orexin-A differentially modulates AMPA-preferring responses of ganglion cells and amacrine cells in rat retina. Neuropharmacology 2015; 93:80-93. [PMID: 25656479 DOI: 10.1016/j.neuropharm.2015.01.016] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2014] [Revised: 12/22/2014] [Accepted: 01/20/2015] [Indexed: 01/18/2023]
Abstract
By activating their receptors (OX1R and OX2R) orexin-A/B regulate wake/sleeping states, feeding behaviors, but the function of these peptides in the retina remains unknown. Using patch-clamp recordings and calcium imaging in rat isolated retinal cells, we demonstrated that orexin-A suppressed α-amino-3-hydroxy-5-methyl-4-isoxazole-propionic acid (AMPA)-preferring receptor-mediated currents (AMPA-preferring currents) in ganglion cells (GCs) through OX1R, but potentiated those in amacrine cells (ACs) through OX2R. Consistently, in rat retinal slices orexin-A suppressed light-evoked AMPA-preferring receptor-mediated excitatory postsynaptic currents in GCs, but potentiated those in ACs. Intracellular dialysis of GDP-β-S or preincubation with the Gi/o inhibitor pertussis toxin (PTX) abolished both the effects. Either cAMP/the protein kinase A (PKA) inhibitor Rp-cAMP or cGMP/the PKG blocker KT5823 failed to alter the orexin-A effects. Whilst both of them involved activation of protein kinase C (PKC), the effects on GCs and ACs were respectively eliminated by the phosphatidylinositol (PI)-phospholipase C (PLC) inhibitor and phosphatidylcholine (PC)-PLC inhibitor. Moreover, in GCs orexin-A increased [Ca(2+)]i and the orexin-A effect was blocked by intracellular Ca(2+)-free solution and by inositol 1,4,5-trisphosphate (IP3) receptor antagonists. In contrast, orexin-A did not change [Ca(2+)]i in ACs and the orexin-A effect remained in intracellular or extracellular Ca(2+)-free solution. We conclude that a distinct Gi/o/PI-PLC/IP3/Ca(2+)-dependent PKC signaling pathway, following the activation of OX1R, is likely responsible for the orexin-A effect on GCs, whereas a Gi/o/PC-PLC/Ca(2+)-independent PKC signaling pathway, following the activation of OX2R, mediates the orexin-A effect on ACs. These two actions of orexin-A, while working in concert, provide a characteristic way for modulating information processing in the inner retina.
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Affiliation(s)
- Chao Zheng
- Institute of Neurobiology, Institutes of Brain Science, State Key Laboratory of Medical Neurobiology and Collaborative Innovation Center for Brain Science, Fudan University, 138 Yixueyuan Road, Shanghai 200032, China; Cell Electrophysiology Laboratory, Wannan Medical College, 22 West Wenchang Road, Wuhu, Anhui 241002, China
| | - Qin-Qin Deng
- Institute of Neurobiology, Institutes of Brain Science, State Key Laboratory of Medical Neurobiology and Collaborative Innovation Center for Brain Science, Fudan University, 138 Yixueyuan Road, Shanghai 200032, China
| | - Lei-Lei Liu
- Institute of Neurobiology, Institutes of Brain Science, State Key Laboratory of Medical Neurobiology and Collaborative Innovation Center for Brain Science, Fudan University, 138 Yixueyuan Road, Shanghai 200032, China
| | - Meng-Ya Wang
- Cell Electrophysiology Laboratory, Wannan Medical College, 22 West Wenchang Road, Wuhu, Anhui 241002, China
| | - Gong Zhang
- Institute of Neurobiology, Institutes of Brain Science, State Key Laboratory of Medical Neurobiology and Collaborative Innovation Center for Brain Science, Fudan University, 138 Yixueyuan Road, Shanghai 200032, China
| | - Wen-Long Sheng
- Institute of Neurobiology, Institutes of Brain Science, State Key Laboratory of Medical Neurobiology and Collaborative Innovation Center for Brain Science, Fudan University, 138 Yixueyuan Road, Shanghai 200032, China
| | - Shi-Jun Weng
- Institute of Neurobiology, Institutes of Brain Science, State Key Laboratory of Medical Neurobiology and Collaborative Innovation Center for Brain Science, Fudan University, 138 Yixueyuan Road, Shanghai 200032, China
| | - Xiong-Li Yang
- Institute of Neurobiology, Institutes of Brain Science, State Key Laboratory of Medical Neurobiology and Collaborative Innovation Center for Brain Science, Fudan University, 138 Yixueyuan Road, Shanghai 200032, China.
| | - Yong-Mei Zhong
- Institute of Neurobiology, Institutes of Brain Science, State Key Laboratory of Medical Neurobiology and Collaborative Innovation Center for Brain Science, Fudan University, 138 Yixueyuan Road, Shanghai 200032, China.
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32
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Prince CD, Rau AR, Yorgason JT, España RA. Hypocretin/Orexin regulation of dopamine signaling and cocaine self-administration is mediated predominantly by hypocretin receptor 1. ACS Chem Neurosci 2015; 6:138-46. [PMID: 25496218 PMCID: PMC4304483 DOI: 10.1021/cn500246j] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
![]()
Extensive
evidence suggests that the hypocretins/orexins influence
cocaine reinforcement and dopamine signaling via actions at hypocretin
receptor 1. By comparison, the involvement of hypocretin receptor
2 in reward and reinforcement processes has received relatively little
attention. Thus, although there is some evidence that hypocretin receptor
2 regulates intake of some drugs of abuse, it is currently unclear
to what extent hypocretin receptor 2 participates in the regulation
of dopamine signaling or cocaine self-administration, particularly
under high effort conditions. To address this, we examined the effects
of hypocretin receptor 1, and/or hypocretin receptor 2 blockade on
dopamine signaling and cocaine reinforcement. We used in vivo fast
scan cyclic voltammetry to test the effects of hypocretin antagonists
on dopamine signaling in the nucleus accumbens core and a progressive
ratio schedule to examine the effects of these antagonists on cocaine
self-administration. Results demonstrate that blockade of either hypocretin
receptor 1 or both hypocretin receptor 1 and 2 significantly reduces
the effects of cocaine on dopamine signaling and decreases the motivation
to take cocaine. In contrast, blockade of hypocretin receptor 2 alone
had no significant effects on dopamine signaling or self-administration.
These findings suggest a differential involvement of the two hypocretin
receptors, with hypocretin receptor 1 appearing to be more involved
than hypocretin receptor 2 in the regulation of dopamine signaling
and cocaine self-administration. When considered with the existing
literature, these data support the hypothesis that hypocretins exert
a permissive influence on dopamine signaling and motivated behavior
via preferential actions on hypocretin receptor 1.
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Affiliation(s)
- Courtney D. Prince
- Department
of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, Pennsylvania 19129, United States
| | - Andrew R. Rau
- Department
of Physiology and Pharmacology, Wake Forest School of Medicine, Winston-Salem, North Carolina 27157, United States
| | - Jordan T. Yorgason
- Vollum
Institute, Oregon Health and Science University, Portland, Oregon 97239, United States
| | - Rodrigo A. España
- Department
of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, Pennsylvania 19129, United States
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Hu B, Yang N, Qiao QC, Hu ZA, Zhang J. Roles of the orexin system in central motor control. Neurosci Biobehav Rev 2014; 49:43-54. [PMID: 25511388 DOI: 10.1016/j.neubiorev.2014.12.005] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2014] [Revised: 11/10/2014] [Accepted: 12/03/2014] [Indexed: 12/15/2022]
Abstract
The neuropeptides orexin-A and orexin-B are produced by one group of neurons located in the lateral hypothalamic/perifornical area. However, the orexins are widely released in entire brain including various central motor control structures. Especially, the loss of orexins has been demonstrated to associate with several motor deficits. Here, we first summarize the present knowledge that describes the anatomical and morphological connections between the orexin system and various central motor control structures. In the next section, the direct influence of orexins on related central motor control structures is reviewed at molecular, cellular, circuitry, and motor activity levels. After the summarization, the characteristic and functional relevance of the orexin system's direct influence on central motor control function are demonstrated and discussed. We also propose a hypothesis as to how the orexin system orchestrates central motor control in a homeostatic regulation manner. Besides, the importance of the orexin system's phasic modulation on related central motor control structures is highlighted in this regulation manner. Finally, a scheme combining the homeostatic regulation of orexin system on central motor control and its effects on other brain functions is presented to discuss the role of orexin system beyond the pure motor activity level, but at the complex behavioral level.
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Affiliation(s)
- Bo Hu
- Department of Physiology, College of Basic Medical Sciences, Third Military Medical University, 30 Gaotanyan Street, Shapingba District, Chongqing 400038, PR China
| | - Nian Yang
- Department of Physiology, College of Basic Medical Sciences, Third Military Medical University, 30 Gaotanyan Street, Shapingba District, Chongqing 400038, PR China
| | - Qi-Cheng Qiao
- Department of Physiology, College of Basic Medical Sciences, Third Military Medical University, 30 Gaotanyan Street, Shapingba District, Chongqing 400038, PR China
| | - Zhi-An Hu
- Department of Physiology, College of Basic Medical Sciences, Third Military Medical University, 30 Gaotanyan Street, Shapingba District, Chongqing 400038, PR China.
| | - Jun Zhang
- Department of Physiology, College of Basic Medical Sciences, Third Military Medical University, 30 Gaotanyan Street, Shapingba District, Chongqing 400038, PR China.
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34
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Horjales-Araujo E, Hellysaz A, Broberger C. Lateral hypothalamic thyrotropin-releasing hormone neurons: distribution and relationship to histochemically defined cell populations in the rat. Neuroscience 2014; 277:87-102. [PMID: 24993479 DOI: 10.1016/j.neuroscience.2014.06.043] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2014] [Revised: 06/13/2014] [Accepted: 06/20/2014] [Indexed: 12/30/2022]
Abstract
The lateral hypothalamic area (LHA) constitutes a large component of the hypothalamus, and has been implicated in several aspects of motivated behavior. The LHA is of particular relevance to behavioral state control and the maintenance of arousal. Due to the cellular heterogeneity of this region, however, only some subpopulations of LHA cells have been properly anatomically characterized. Here, we have focused on cells expressing thyrotropin-releasing hormone (TRH), a peptide found in the LHA that has been implicated as a promoter of arousal. Immunofluorescence and in situ hybridization were used to map the LHA TRH population in the rat, and cells were observed to form a large ventral cluster that extended throughout almost the entire rostro-caudal axis of the hypothalamus. Almost no examples of coexistence were seen when sections were double-stained for TRH and markers of other LHA populations, including the peptides hypocretin/orexin, melanin-concentrating hormone and neurotensin. In the juxtaparaventricular area, however, a discrete group of TRH-immunoreactive cells were also stained with antisera against enkephalin and urocortin 3. Innervation from the metabolically sensitive hypothalamic arcuate nucleus was investigated by double-staining for peptide markers of the two centrally projecting groups of arcuate neurons, agouti gene-related peptide and α-melanocyte-stimulating hormone, respectively; both populations of terminals were observed forming close appositions on TRH cells in the LHA. The present study indicates that TRH-expressing cells form a unique population in the LHA that may serve as a link between metabolic signals and the generation of arousal.
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Affiliation(s)
- E Horjales-Araujo
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - A Hellysaz
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - C Broberger
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden.
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Abstract
The basic elements of animal behavior that are critical to survival include energy, arousal, and motivation: Energy intake and expenditure are fundamental to all organisms for the performance of any type of function; according to the Yerkes-Dodson law, an optimal level of arousal is required for animals to perform normal functions; and motivation is critical to goal-oriented behaviors in higher animals. The brain is the primary organ that controls these elements and, through evolution, has developed specialized structures to accomplish this task. The orexin/hypocretin system in the perifornical/lateral hypothalamus, which was discovered 15 years ago, is one such specialized area. This review summarizes a fast-growing body of evidence discerning how the orexin/hypocretin system integrates internal and external cues to regulate energy intake that can then be used to generate sufficient arousal for animals to perform innate and goal-oriented behaviors.
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Affiliation(s)
- Xiao-Bing Gao
- Yale Program in Integrative Cell Signaling and Neurobiology of Metabolism, Section of Comparative Medicine, Yale University School of Medicine, New Haven, Connecticut 06520; ,
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Oh Y, Jang D, Sonn JY, Choe J. Histamine-HisCl1 receptor axis regulates wake-promoting signals in Drosophila melanogaster. PLoS One 2013; 8:e68269. [PMID: 23844178 PMCID: PMC3700972 DOI: 10.1371/journal.pone.0068269] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2013] [Accepted: 05/29/2013] [Indexed: 12/21/2022] Open
Abstract
Histamine and its two receptors, histamine-gated chloride channel subunit 1 (HisCl1) and ora transientless (Ort), are known to control photoreception and temperature sensing in Drosophila. However, histamine signaling in the context of neural circuitry for sleep-wake behaviors has not yet been examined in detail. Here, we obtained mutant flies with compromised or enhanced histamine signaling and tested their baseline sleep. Hypomorphic mutations in histidine decarboxylase (HDC), an enzyme catalyzing the conversion from histidine to histamine, caused an increase in sleep duration. Interestingly, hisCl1 mutants but not ort mutants showed long-sleep phenotypes similar to those in hdc mutants. Increased sleep duration in hisCl1 mutants was rescued by overexpressing hisCl1 in circadian pacemaker neurons expressing a neuropeptide pigment dispersing factor (PDF). Consistently, RNA interference (RNAi)-mediated depletion of hisCl1 in PDF neurons was sufficient to mimic hisCl1 mutant phenotypes, suggesting that PDF neurons are crucial for sleep regulation by the histamine-HisCl1 signaling. Finally, either hisCl1 mutation or genetic ablation of PDF neurons dampened wake-promoting effects of elevated histamine signaling via direct histamine administration. Taken together, these data clearly demonstrate that the histamine-HisCl1 receptor axis can activate and maintain the wake state in Drosophila and that wake-activating signals may travel via the PDF neurons.
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Affiliation(s)
- Yangkyun Oh
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon, Republic of Korea
| | - Donghoon Jang
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon, Republic of Korea
| | - Jun Young Sonn
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon, Republic of Korea
| | - Joonho Choe
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon, Republic of Korea
- * E-mail:
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37
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Mahoney CE, McKinley Brewer J, Bittman EL. Central control of circadian phase in arousal-promoting neurons. PLoS One 2013; 8:e67173. [PMID: 23826226 PMCID: PMC3691112 DOI: 10.1371/journal.pone.0067173] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2012] [Accepted: 05/14/2013] [Indexed: 11/18/2022] Open
Abstract
Cells of the dorsomedial/lateral hypothalamus (DMH/LH) that produce hypocretin (HCRT) promote arousal in part by activation of cells of the locus coeruleus (LC) which express tyrosine hydroxylase (TH). The suprachiasmatic nucleus (SCN) drives endogenous daily rhythms, including those of sleep and wakefulness. These circadian oscillations are generated by a transcriptional-translational feedback loop in which the Period (Per) genes constitute critical components. This cell-autonomous molecular clock operates not only within the SCN but also in neurons of other brain regions. However, the phenotype of such neurons and the nature of the phase controlling signal from the pacemaker are largely unknown. We used dual fluorescent in situ hybridization to assess clock function in vasopressin, HCRT and TH cells of the SCN, DMH/LH and LC, respectively, of male Syrian hamsters. In the first experiment, we found that Per1 expression in HCRT and TH oscillated in animals held in constant darkness with a peak phase that lagged that in AVP cells of the SCN by several hours. In the second experiment, hamsters induced to split their locomotor rhythms by exposure to constant light had asymmetric Per1 expression within cells of the middle SCN at 6 h before activity onset (AO) and in HCRT cells 9 h before and at AO. We did not observe evidence of lateralization of Per1 expression in the LC. We conclude that the SCN communicates circadian phase to HCRT cells via lateralized neural projections, and suggests that Per1 expression in the LC may be regulated by signals of a global or bilateral nature.
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Affiliation(s)
- Carrie E. Mahoney
- Neuroscience and Behavior Program, University of Massachusetts, Amherst, Massachusetts, United States of America
| | - Judy McKinley Brewer
- Neuroscience and Behavior Program, University of Massachusetts, Amherst, Massachusetts, United States of America
- Department of Biology, University of Massachusetts, Amherst, Massachusetts, United States of America
| | - Eric L. Bittman
- Neuroscience and Behavior Program, University of Massachusetts, Amherst, Massachusetts, United States of America
- Department of Biology, University of Massachusetts, Amherst, Massachusetts, United States of America
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38
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Chase MH. A unified survival theory of the functioning of the hypocretinergic system. J Appl Physiol (1985) 2013; 115:954-71. [PMID: 23640599 DOI: 10.1152/japplphysiol.00700.2012] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
This article advances the theory that the hypocretinergic (orexinergic) system initiates, coordinates, and maintains survival behaviors and survival-related processes (i.e., the Unified Survival Theory of the Functioning of the Hypocretinergic System or "Unified Hypocretinergic Survival Theory"). A priori presumptive support for the Unified Hypocretinergic Survival Theory emanates from the fact that neurons that contain hypocretin are located in the key executive central nervous system (CNS) site, the lateral hypothalamus, that for decades has been well-documented to govern core survival behaviors such as fight, flight, and food consumption. In addition, the hypocretinergic system exhibits the requisite morphological and electrophysiological capabilities to control survival behaviors and related processes. Complementary behavioral data demonstrate that all facets of "survival" are coordinated by the hypocretinergic system and that hypocretinergic directives are not promulgated except during survival behaviors. Importantly, it has been shown that survival behaviors are selectively impacted when the hypocretinergic system is impaired or rendered nonfunctional, whereas other behaviors are relatively unaffected. The Unified Hypocretinergic Survival Theory resolves the disparate, perplexing, and often paradoxical-appearing results of previous studies; it also provides a foundation for future hypothesis-driven basic science and clinical explorations of the hypocretinergic system.
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Affiliation(s)
- Michael H Chase
- WebSciences International, Veterans Affairs-Greater Los Angeles Healthcare System, University of California, Los Angeles School of Medicine, Los Angeles, California
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García-García B, Reinoso-Suárez F, Rodrigo-Angulo ML. Hypothalamic Hypocretinergic/Orexinergic Neurons Projecting to the Oral Pontine Rapid Eye Movement Sleep Inducing Site in the Cat. Anat Rec (Hoboken) 2013; 296:815-21. [DOI: 10.1002/ar.22690] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2012] [Accepted: 12/19/2012] [Indexed: 11/06/2022]
Affiliation(s)
- Berta García-García
- Departamento de Anatomía; Histología y Neurociencia, Facultad de Medicina, Universidad Autónoma de Madrid; Madrid Spain
| | - Fernando Reinoso-Suárez
- Departamento de Anatomía; Histología y Neurociencia, Facultad de Medicina, Universidad Autónoma de Madrid; Madrid Spain
| | - Margarita L. Rodrigo-Angulo
- Departamento de Anatomía; Histología y Neurociencia, Facultad de Medicina, Universidad Autónoma de Madrid; Madrid Spain
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40
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Abstract
The hypocretin (also known as orexin) system reacts to environmental changes in the internal milieu (pH, glucose, and various hormones) and the external environment (activity, fasting, and sleep deprivation) and regulates various physiological functions. Several feedback mechanisms, such as those listed above, have been reported to regulate the hypocretin system even at the transcriptional level. In addition, some transcription factors, such as forkhead box A2; nuclear receptor subfamily 6, group A, member 1; and early B-cell factor 2, were determined to be regulators of the preprohypocretin gene. However, little is known concerning the specific components that react to environmental changes and the determinants of spatial expression of the hypocretin gene within the lateral hypothalamus. This review focuses on the recent findings of transcription factors that regulate preprohypocretin transcription in addition to discussing the future prospects for transcriptional regulation of the hypocretin gene.
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Affiliation(s)
- Susumu Tanaka
- Department of Psychiatry and Behavioral Science, Tokyo Metropolitan Institute of Medical Science, Setagaya-ku, Tokyo, Japan
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Poca MA, Galard R, Serrano E, Merino MA, Pozo-Rosich P, Solana E, Mestres O, de la Calzada MD, Sahuquillo J. Normal Hypocretin-1 (Orexin A) Levels in Cerebrospinal Fluid in Patients with Idiopathic Intracranial Hypertension. ACTA NEUROCHIRURGICA SUPPLEMENTUM 2012; 114:221-5. [DOI: 10.1007/978-3-7091-0956-4_43] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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Liu F, Xu G, Wang L, Jiang S, Yang X, Zhong Y. Gene expression and protein distribution of orexins and orexin receptors in rat retina. Neuroscience 2011; 189:146-55. [DOI: 10.1016/j.neuroscience.2011.04.011] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2011] [Revised: 03/18/2011] [Accepted: 04/04/2011] [Indexed: 12/24/2022]
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Fenzl T, Romanowski CPN, Flachskamm C, Deussing JM, Kimura M. Wake-promoting effects of orexin: Its independent actions against the background of an impaired corticotropine-releasing hormone receptor system. Behav Brain Res 2011; 222:43-50. [PMID: 21420442 DOI: 10.1016/j.bbr.2011.03.026] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2011] [Revised: 03/04/2011] [Accepted: 03/11/2011] [Indexed: 01/08/2023]
Abstract
It is widely accepted that orexin (hypocretin) bears wake-promoting effects. While under normal conditions the circadian rhythm of orexin release has a clear circadian distribution, the amplitude of orexin fluctuation is dampened in depression. Interestingly, clinical symptoms of depression include several sleep disturbances. In this disease, corticotropin-releasing hormone (CRH) seems to be another factor influencing sleep. As neurophysiological interactions and anatomical connections between the orexinergic and the CRH system point to mutual influences of these two neuropeptides, we examined whether a dysfunctional CRH-receptor system in two different CRH receptor knock out models alters general wake-promoting effects of orexin applied exogenously. Orexin was injected intracerebroventricularlly into CNS-restricted CRH-receptor type 1 knockout mice (CRH-R1 KO) and CRH-receptor type 2 knockout mice (CRH-R2 KO) and baseline sleep was recorded from the freely behaving mice. A third experiment included antisauvagine-30 injections (CRH-R2 antagonist) into CRH-R1 KO animals. Orexin had similar wake-promoting effects in CRH-R1KO mice, in CRH-R2 KO animals and in CRH-R1KO mice treated with antisauvagine-30. Consistent results were obtained from all corresponding control littermate experiments. According to our results we conclude that the wake-promoting effects of orexin are not influenced by a possible contribution of CRH.
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Affiliation(s)
- Thomas Fenzl
- Max-Planck-Institute of Psychiatry, Kraepelinstrasse 2, 80804 Munich, Germany.
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Perrey DA, Gilmour BP, Runyon SP, Thomas BF, Zhang Y. Diaryl urea analogues of SB-334867 as orexin-1 receptor antagonists. Bioorg Med Chem Lett 2011; 21:2980-5. [PMID: 21478014 DOI: 10.1016/j.bmcl.2011.03.048] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2011] [Revised: 03/11/2011] [Accepted: 03/14/2011] [Indexed: 10/18/2022]
Abstract
As a part of our program to develop OX1-CB1 bivalent ligands, we required a better understanding of the basic structure-activity relationships (SARs) of orexin antagonists. A series of SB-334867 analogues were synthesized and evaluated in calcium mobilization assays. SAR results suggest that the 2-methylbenzoxazole moiety may be replaced with a disubstituted 4-aminophenyl group without loss of activity and an electron-deficient system is generally preferred at the 1,5-naphthyridine moiety for OX1 antagonist activity. In particular, substitution of larger potential linkers such as n-hexyl provided compound 33 with equivalent activity at the OX1 receptor compared to the lead compound SB-334867. These compounds should be of value in the development of ligands targeting the orexin-1 receptor and its potential heterodimers.
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Affiliation(s)
- David A Perrey
- Research Triangle Institute, 3040 Cornwallis Road, Research Triangle Park, NC 27709, USA
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Uschakov A, Grivel J, Cvetkovic-Lopes V, Bayer L, Bernheim L, Jones BE, Mühlethaler M, Serafin M. Sleep-deprivation regulates α-2 adrenergic responses of rat hypocretin/orexin neurons. PLoS One 2011; 6:e16672. [PMID: 21347440 PMCID: PMC3035660 DOI: 10.1371/journal.pone.0016672] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2010] [Accepted: 12/31/2010] [Indexed: 12/11/2022] Open
Abstract
We recently demonstrated, in rat brain slices, that the usual excitation by noradrenaline (NA) of hypocretin/orexin (hcrt/orx) neurons was changed to an inhibition following sleep deprivation (SD). Here we describe that in control condition (CC), i.e. following 2 hours of natural sleep in the morning, the α(2)-adrenergic receptor (α(2)-AR) agonist, clonidine, had no effect on hcrt/orx neurons, whereas following 2 hours of SD (SDC), it hyperpolarized the neurons by activating G-protein-gated inwardly rectifying potassium (GIRK) channels. Since concentrations of clonidine up to a thousand times (100 µM) higher than those effective in SDC (100 nM), were completely ineffective in CC, a change in the availability of G-proteins is unlikely to explain the difference between the two conditions. To test whether the absence of effect of clonidine in CC could be due to a down-regulation of GIRK channels, we applied baclofen, a GABA(B) agonist known to also activate GIRK channels, and found that it hyperpolarized hcrt/orx neurons in that condition. Moreover, baclofen occluded the response to clonidine in SDC, indicating that absence of effect of clonidine in CC could not be attributed to down-regulation of GIRK channels. We finally tested whether α(2)-ARs were still available at the membrane in CC and found that clonidine could reduce calcium currents, indicating that α(2)-ARs associated with calcium channels remain available in that condition. Taken together, these results suggest that a pool of α(2)-ARs associated with GIRK channels is normally down-regulated (or desensitized) in hcrt/orx neurons to only become available for their inhibition following sleep deprivation.
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Affiliation(s)
- Aaron Uschakov
- Département de Neurosciences fondamentales, Centre Médical Universitaire, Genève, Switzerland
| | - Jeremy Grivel
- Département de Neurosciences fondamentales, Centre Médical Universitaire, Genève, Switzerland
| | - Vesna Cvetkovic-Lopes
- Département de Neurosciences fondamentales, Centre Médical Universitaire, Genève, Switzerland
| | - Laurence Bayer
- Département de Neurosciences fondamentales, Centre Médical Universitaire, Genève, Switzerland
| | - Laurent Bernheim
- Département de Neurosciences fondamentales, Centre Médical Universitaire, Genève, Switzerland
| | - Barbara E. Jones
- Department of Neurology and Neurosurgery, McGill University, Montreal Neurological Institute, Montreal, Quebec, Canada
| | - Michel Mühlethaler
- Département de Neurosciences fondamentales, Centre Médical Universitaire, Genève, Switzerland
| | - Mauro Serafin
- Département de Neurosciences fondamentales, Centre Médical Universitaire, Genève, Switzerland
- * E-mail:
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Cvetkovic-Lopes V, Eggermann E, Uschakov A, Grivel J, Bayer L, Jones BE, Serafin M, Mühlethaler M. Rat hypocretin/orexin neurons are maintained in a depolarized state by TRPC channels. PLoS One 2010; 5:e15673. [PMID: 21179559 PMCID: PMC3002943 DOI: 10.1371/journal.pone.0015673] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2010] [Accepted: 11/19/2010] [Indexed: 12/14/2022] Open
Abstract
In a previous study we proposed that the depolarized state of the wake-promoting hypocretin/orexin (hcrt/orx) neurons was independent of synaptic inputs as it persisted in tetrodotoxin and low calcium/high magnesium solutions. Here we show first that these cells are hyperpolarized when external sodium is lowered, suggesting that non-selective cation channels (NSCCs) could be involved. As canonical transient receptor channels (TRPCs) are known to form NSCCs, we looked for TRPCs subunits using single-cell RT-PCR and found that TRPC6 mRNA was detectable in a small minority, TRPC1, TRPC3 and TRPC7 in a majority and TRPC4 and 5 in the vast majority (∼90%) of hcrt/orx neurons. Using intracellular applications of TRPC antibodies against subunits known to form NSCCs, we then found that only TRPC5 antibodies elicited an outward current, together with hyperpolarization and inhibition of the cells. These effects were blocked by co-application of a TRPC5 antigen peptide. Voltage-clamp ramps in the presence or absence of TRPC5 antibodies indicated the presence of a current with a reversal potential close to -15 mV. Application of the non-selective TRPC channel blocker, flufenamic acid, had a similar effect, which could be occluded in cells pre-loaded with TRPC5 antibodies. Finally, using the same TRPC5 antibodies we found that most hcrt/orx cells show immunostaining for the TRPC5 subunit. These results suggest that hcrt/orx neurons are endowed with a constitutively active non-selective cation current which depends on TRPC channels containing the TRPC5 subunit and which is responsible for the depolarized and active state of these cells.
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Affiliation(s)
- Vesna Cvetkovic-Lopes
- Département de Neurosciences Fondamentales, Centre Médical Universitaire, Genève, Switzerland
| | - Emmanuel Eggermann
- Département de Neurosciences Fondamentales, Centre Médical Universitaire, Genève, Switzerland
| | - Aaron Uschakov
- Département de Neurosciences Fondamentales, Centre Médical Universitaire, Genève, Switzerland
| | - Jeremy Grivel
- Département de Neurosciences Fondamentales, Centre Médical Universitaire, Genève, Switzerland
| | - Laurence Bayer
- Département de Neurosciences Fondamentales, Centre Médical Universitaire, Genève, Switzerland
| | - Barbara E. Jones
- Department of Neurology and Neurosurgery, McGill University, Montreal Neurological Institute, Montreal, Quebec, Canada
| | - Mauro Serafin
- Département de Neurosciences Fondamentales, Centre Médical Universitaire, Genève, Switzerland
| | - Michel Mühlethaler
- Département de Neurosciences Fondamentales, Centre Médical Universitaire, Genève, Switzerland
- * E-mail:
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Rinkwitz S, Mourrain P, Becker TS. Zebrafish: an integrative system for neurogenomics and neurosciences. Prog Neurobiol 2010; 93:231-43. [PMID: 21130139 DOI: 10.1016/j.pneurobio.2010.11.003] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2010] [Revised: 11/08/2010] [Accepted: 11/22/2010] [Indexed: 10/18/2022]
Abstract
Rapid technological advances over the past decade have moved us closer to a high throughput molecular approach to neurobiology, where we see the merging of neurogenetics, genomics, physiology, imaging and pharmacology. This is the case more in zebrafish than in any other model organism commonly used. Recent improvements in the generation of transgenic zebrafish now allow genetic manipulation and live imaging of neuronal development and function in early embryonic, larval, and adult animals. The sequenced zebrafish genome and comparative genomics give unprecedented insights into genome evolution and its relation to genome structure and function. There is now information on embryonic and larval expression of over 12,000 genes and just under 1000 mutant phenotypes. We review the remarkable similarity of the zebrafish genetic blueprint for the nervous system to that of mammals and assess recent technological advances that make the zebrafish a model of choice for elucidating the development and function of neuronal circuitry, transgene-based neuroanatomy, and small molecule neuropharmacology.
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Affiliation(s)
- Silke Rinkwitz
- Brain and Mind Research Institute, Sydney Medical School, University of Sydney, 100 Mallett St., Camperdown, NSW 2050, Australia
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Tanaka S, Kodama T, Nonaka T, Toyoda H, Arai M, Fukazawa M, Honda Y, Honda M, Mignot E. Transcriptional regulation of the hypocretin/orexin gene by NR6A1. Biochem Biophys Res Commun 2010; 403:178-83. [PMID: 21056546 DOI: 10.1016/j.bbrc.2010.11.001] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2010] [Accepted: 11/01/2010] [Indexed: 12/30/2022]
Abstract
The hypocretin (also known as orexin) neuropeptide system coordinates the regulation of various physiological processes. A reduction in Nr6a1 expression was observed in hypocretin neuron-ablated transgenic mice. To show that prepro-hypocretin transcription is functionally modulated by NR6A1, we performed chromatin immunoprecipitation (ChIP) analysis, double-immunostaining, a luciferase reporter assay, and an in utero electroporation study. ChIP analysis showed that endogenous NR6A1 binds to a putative NR6A1-binding site. Double-immunostaining indicated almost all hypocretin neurons were positive for NR6A1 immunoreactivity. NR6A1 overexpression in SH-SY5Y cells modulated hypocretin promoter activity, an effect that was countered by lacking a putative NR6A1-binding site. Electroporation with Nr6a1 in the foetal hypothalamus promoted hypocretin transcription as compared to GFP-electroporation. These experiments confirmed that NR6A1 works as a regulator for hypocretin transcription.
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Affiliation(s)
- Susumu Tanaka
- Department of Sleep Disorders Research, Tokyo Institute of Psychiatry, Tokyo, Japan.
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Morselli L, Leproult R, Balbo M, Spiegel K. Role of sleep duration in the regulation of glucose metabolism and appetite. Best Pract Res Clin Endocrinol Metab 2010; 24:687-702. [PMID: 21112019 PMCID: PMC3018785 DOI: 10.1016/j.beem.2010.07.005] [Citation(s) in RCA: 168] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Sleep curtailment has become a common behavior in modern society. This review summarizes the current laboratory evidence indicating that sleep loss may contribute to the pathophysiology of diabetes mellitus and obesity. Experimentally induced sleep loss in healthy volunteers decreases insulin sensitivity without adequate compensation in beta-cell function, resulting in impaired glucose tolerance and increased diabetes risk. Lack of sleep also down-regulates the satiety hormone leptin, up-regulates the appetite-stimulating hormone ghrelin, and increases hunger and food intake. Taken together with the epidemiologic evidence for an association between short sleep and the prevalence or incidence of diabetes mellitus and/or obesity, these results support a role for reduced sleep duration in the current epidemic of these metabolic disorders. Screening for habitual sleep patterns in patients with "diabesity" is therefore of great importance. Studies are warranted to investigate the putative therapeutic impact of extending sleep in habitual short sleepers with metabolic disorders.
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Sánchez-de-la-Torre M, Pierola J, Vidal C, Barceló A, de la Peña M, Hussain Z, Capote F, Durán J, Agustí AGN, de Lecea L, Torres G, Esquinas C, Martinez M, Barbé F. Non-synonymous polymorphism in the neuropeptide S precursor gene and sleep apnea. Sleep Breath 2010; 15:403-8. [PMID: 20405330 DOI: 10.1007/s11325-010-0348-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2009] [Revised: 03/09/2010] [Accepted: 03/30/2010] [Indexed: 11/29/2022]
Abstract
BACKGROUND Obstructive sleep apnea syndrome (OSAS) is a complex disease with a strong genetic basis. One of the primary molecular domains affected by OSAS is sympathetic activity. Neuropeptide S (NPS) plays an important role in the regulation of the sleep-wakefulness cycle, anxiety states, and daytime sleepiness. It is important to study neuropeptides related to sympathetic activity regulation and how their function could be modified by genetic variants affecting the expression of these molecules. OBJECTIVES We investigated the association of the non-synonymous polymorphism rs4751440 in the NPS precursor gene with OSAS and certain variables related to OSAS (daytime sleepiness, body mass index (BMI), insulin resistance, and blood pressure). This polymorphism causes an amino acid substitution in exon 3 of the human NPS precursor gene. PATIENTS AND METHODS We included 253 OSAS patients and 70 healthy subjects. Genotyping was done by polymerase chain reaction using specific flanking primers and agarose gel electrophoresis. Daytime sleepiness, BMI, plasma levels of high-density lipoprotein, glucose, total cholesterol, insulin, triglycerides, and the homeostasis model assessment index were also determined. RESULTS A similar genotypic and allelic distribution was found in OSAS patients and controls. The risk of OSAS was not associated with the rs4751440 polymorphism. There was no significant interaction between daytime sleepiness or metabolic variables and the rs4751440 polymorphism. CONCLUSION Genotypic and allelic frequency distribution of the rs4751440 polymorphism was similar in OSAS patients and controls. In this population-based study, we could not show a significant association between rs4751440 polymorphism and susceptibility to OSAS or certain phenotypes related to OSAS (daytime sleepiness, BMI, systolic blood pressure, and insulin resistance) with the exception of diastolic blood pressure.
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